This invention relates to thermostats. More particularly this invention relates to a thermostat including configurable multi-level backlighting.
Typically a thermostat is provided for controlling a heating and cooling system within a building. The thermostat selectively actuates the heating and cooling system to provide a desired temperature. Conventional thermostats include a temperature sensitive device for indicating the temperature and activating the heating and cooling system. Typically, such devices are sensitive to relatively small changes of temperature.
A known feature for a thermostat is to include a backlight display such that the thermostat can be read and adjusted at night without turning on lights. Typically, the backlight is either continuously on, or is actuated at the first touch of a button on the thermostat and maintained for a reasonable amount of time following the release of the button. Both configurations have certain disadvantages. Continuous backlighting generates heat that can affect the accuracy of the temperature-sensing device within the thermostat. Backlighting that engages when a control button is pushed prevents the simple monitoring of the thermostat without interacting with the thermostat. Additionally, actuating lighting in response to a button being pressed complicates the programming and operation of the thermostat. Determining whether an operator merely wishes to observe current conditions, or actually change a setting complicates programming and most often results in a compromise that does not fully accommodate either instance fully.
For these reasons, it is desirable to develop a thermostat that includes configurable lighting that does not adversely affect thermostat functions.